Crimping apparatus

ABSTRACT

THIS INVENTION RELATES TO AN IMPROVEMENT IN APPARATUS FOR TREATING TEXTILE MATERIALS HAVING A SET OF OPPOSED SURFACES WHEREIN ONE OF THE SURFACES IS ENGRAVED WITH A PATTERN AND THE OTHER SURFACE IS MADE FROM A RESILIENT MATERIAL CAPABLE OF BEING DEFORMED INTO A CONFIGURATION WHICH MATCHES THAT OF THE FIRST SURFACE WHEN THE TWO SURFACES ARE BROUGHT INTO CONTACT WITH EACH OTHER UNDER HEAT AND PRESSURE, THE IMPROVEMENT COMPRISING HAVING UNENGRAVED SHOULDER PORTIONS ON EACH SIDE OF THE ENGRAVED PATTERN IN THE TOP ROLL AND EXTENDING ABOVE THE ENGRAVED PORTION OF THE TOP OF THE SHOULDER PORTIONS WHEREBY THE PRESSURE IS EQUALIZED ACROSS THE COMPLETE WIDTH OF THE BOTTOM ROLL WHEN THE TWO ROLLS ARE BROUGHT INTO CONTACT WITH EACH OTHER.

Feb. 16, 1971 H, D Y RBER 3,562,880

CRIMPING APPARATUS Filed Aug. 9, 1968 INVENTOR. HAROLD D. YARBER BY M QWLM ATTORNEY United States Patent 3,562,880 CRIMPING APPARATUS Harold D. Yarber, Wallace, N.C., assignor to J. P. Stevens & Co., Inc., New York, N.Y., a corporation of Delaware Filed Aug. 9, 1968, Ser. No. 751,565 Int. Cl. D02g 1/14 U.S. Cl. 281.8 3 Claims ABSTRACT OF THE DISCLOSURE This invention relates to an improvement in apparatus for treating textile materials having a set of opposed surfaces wherein one of the surfaces is engraved with a pattern and the other surface is made from a resilient material capable of being deformed into a configuration which matches that of the first surface when the two surfaces are brought into contact with each other under heat and pressure, the improvement comprising having unengraved shoulder portions on each side of the engraved pattern in the top roll and extending above the engraved portion of the top of the shoulder portions whereby the pressure is equalized across the complete width of the bottom roll when the two rolls are brought into contact with each other.

This invention relates to an apparatus for treating fibrous material. In one aspect it relates to an apparatus for crimping or forming permanent undulations in normally straight filamentary material formed from various synthetic compositions.

A substantial portion of the textile industry is at present directed towards the preparation and production of yarns and fabrics from synthetic filaments and fibers. These synthetic filaments have a number of highly desirable characteristics such as low cost, long wear and the like. However, due to their synthetic nature, certain physical characteristics common to the natural fibers such as wool, cotton, etc., are not present in the synthetic filaments. For instance, the fibers of wool in their natural form contain a plurality of crimps consisting of waves, which are approximately sinusoidal in form whereby the number of crimps per inch in the individual fibers vary widely with the different grades of Wool. It has been determined that these crimps are primarily responsible for the softer feel and warmth in wool as the crimps tend to hold the individual fibers in the wool yarn apart. Furthermore, the peculiar elastic qualities of wool are thought to stem in some degree from these crimps as when the fibers are stretched, the crimps are more or less straightened and in the straightened condition they have a spring-like tension which tends to return to the wave of the crimped fiber.

Many constructions have been proposed for providing such crimps or waves in synthetic filaments, one of the most common of which comprises rotary means such as a pair of co-operating tooth rolls with intermeshing teeth which advance the filaments while deforming the filaments into the particular crimp pattern or number of crimps per inch desired.

A patent entitled Process and Apparatus For Tex turizing Textile Material issued to J. P. Hollihan et al. on Oct. 10, 1967, No. 3,345,718, describes an apparatus for texturing synthetic filamentary material. This apparatus comprises a set of opposed surfaces having alter nately depressed and raised areas which engage each other wherein at least one of the surfaces is resilient and substantially permanently grooved by the remaining surface which is substantially non-resilient in nature. The apparatus also includes means for moving the surfaces into contact and maintaining them in engagement under pressure, such as hydraulic means and the like, as well as means for feeding textile material between the surfaces in a substantially tensionless state, and means for taking up the textile material under controlled tension after it passes from between the surfaces.

The top roll is fabricated from a relatively hard material such as steel. In such a situation the surface of the top roll is contoured by engraving or other similar procedures by which a desired pattern of raised and depressed areas is cut into the surface. On the other hand, the bottom roll is constructed of a suitable compacted composition or the like which has a durometer hardness in the range of about 72 to and preferably in a range of from about 80 to 86. In practice the resilient roll is fabricated from a blend of about 65% cotton and 35% wool which is resin-impregnated and pressed to have a durometer hardness in the range expressed hereinabove.

This patent also teaches a convenient method for shaping or contouring the surface of the deformable bottom roll in which the surface of the bottom roll is wetted by sponging and the top roll is heated to a temperature of approximately C. after which the bottom roll is forced against the top roll under pressure of about 240 lbs. per linear inch. The top roll is then driven at a linear velocity of approximately 50 feet per minute for a period of approximately 15 minutes. The bottom roll is then released from contact with the roll and is wetted once more. The temperature of the top roll is increased to approximately C. and the bottom roll is once more pressed against it under a pressure of about 400 lbs. per linear inch. Once again the roll is driven at a linear speed of approximately 50 feet per minute for a period of about 15 minutes. The procedure is then repeated as often as is necessary, using increasing pressures, until the contour of the top roll is substantially impressed to form upon the surface of the bottom roll.

The resiliency of the bottom roll helps to prevent breaking or cutting of the textile material passing between the rolls. The use of a resilient roll helps to avoid the buildup of undesirable excessive pressure by sharing the pressure load. In other words, excessive pressure at any point or area between the surfaces of the rolls is relieved since the resilient roll will be deformed thereby preventing any undue strain upon the materials passing between the rolls.

However a problem in maintaining uniformity in the crimps located along the individual fibers of the filamentary material did develop. It was discovered that the top roll was exerting maximum pressure at each individual point of contact with the filamentary material passing between the two rolls so as to in many cases cause breakage of the individual filaments. In addition, the pressure of the top roll on the soft bottom roll caused an undue wearing thereby too often requiring costly replacements.

Therefore it is an object of the present invention to provide an engraved configuration for the top roll whereby a more even distribution of the pressure at the various points of contact between the two rolls could be obtained thereby reducing the possibility of damage to the textile material;

Another object of this invention is to provide an improved top roll which will eliminate side-to-side variation in the pressure of the roll which would otherwise be imparted to the textile material and thereby provide a greater uniformity of the crimps produced in the various filaments passing inside the roll;

Yet another object of this invention is to provide a new and improved crimping apparatus for filamentary material in which the material may be formed with a crimping pattern throughout all of the filaments in the material and in which virtually all breaking or cutting of the filaments during the crimping operation is eliminated;

A still further object of this invention provides a new and improved crimping apparatus which produces a crimp filament in any predetermined pattern that is permanent in nature which is simple in construction and which may be operated efiiciently for prolonged periods of time while continuously producing a uniformly crimped end product which is substantially devoid of breaks in the filaments;

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description which is to be considered in connection with the accompanying drawings wherein:

FIG. 1 is a front plan view of a preferred embodiment of the subject invention;

FIG. 2 is part of a cross-section of the top roll of FIG. 1 taken on the line 22 in FIG. 1 to show the surface area of the top roll;

FIG. 3 is a front plan view of another embodiment of the top roll wherein the rows of teeth lie in a plane horizontal to the plane of the roll.

Briefly this invention relates to an improvement in a texturizing apparatus having a set of opposed surfaces wherein a first surface possesses a number of teeth spaced substantially evenly around the periphery and the width thereof, a second surface made from a sufficiently resilient composition so as to be capable of being deformed into a toothed configuration which matches that of the first surface when the two surfaces are brought into contact with each other under heat and pressure, the improvement in combination therewith comprising unengraved shoulder portions located on each side of the tooth portion of the first surface and a toothed portion extending at least onethird of the tooth length above the shoulder portions whereby a more uniform distribution of pressure is achieved when the two surfaces are brought into contact.

As specifically illustrative of the invention, there is shown in FIG. 1 a crimping apparatus constructed in accordance with the invention for forming a plurality of crimps or waves in fibrous material. Although this crimping apparatus may be employed to crimp a wide variety of fibrous material, in the specific embodiment illustrated it is preferably employed to simultaneously crimp a large number of ends of a fibrous textile material, and comprises a pair of cooperating rolls 1 and 3 which are fixably mounted on rotatable shafts 5 and 7 respectively. [Drive roll 1 is rotated by means not shown and roll 3 is driven as a result of the frictional force resulting from the pressure contact with roll 1.

Roll 1 is fabricated from a relatively hard material such as steel whereas roll 3 is made of a resilient material. It such a situation the surface of the hard roll is contoured by engraving or other similar procedures by which a desired pattern of raised and depressed areas, defining teeth 13, is cut into its surface. On the other hand, the resilient roll 3 is constructed of a suitable compacted composition or the like which has a durometer hardness in the range of about 72 to 100 and preferably in a range of from 80 to 86. (ASTM designation Dl48459.) For example, the resilient roll 3 can be suitably fabricated from a blend of about 65% cotton and wool, which is resin-impregnated and pressed to have a durometer hardness in the ranges expressed hereinabove.

This construction was described in more detail in the patent referred to hereinabove.

Shoulder portions 9 and 11 are positioned on each side of the engraved part of the upper roll 1. The width of each of these shoulder portions ranges from 5.3 to 11.7% of the total width of the roll 1 and preferably is 7.4% of the total width of the roll 1.

FIG. 1 shows upper roll 1 pressed down into resilient roll 3 until the unengraved shoulder portions of roll 1 contact the surface of roll 3. In this manner a central por- 4 tion of roll 3 is forced into the configuration of the engraved portion of roll 1.

As shown in FIG. 2 the teeth 13 are arranged in a helical pattern and are positioned so that the faces 14 of each tooth extend at an angle of approximately 26 with the axis of roll 1. The helical configuration is used to avoid pattern repeats in a fabric woven or knitted from material processed in accordance with the invention. However it is to be appreciated that such pattern repeats can be avoided through selection of weave construction and control of other variables.

FIG. 3 shows another embodiment in which the tops of teeth 13' define lines which are parallel to the axis of roll 1.

Another important part of my improved construction of the top roll is to extend the engraved toothed portion above the level of shoulders 9 and 11.

The depth [1 of teeth 13 is dependent in part on the spacing of the teeth, that is to say, the maximum depth is limited by the requisite tooth area configuration needed to withstand the pressures necessary for the crimping operation. Aside from this consideration a deeper groove provides a greater texturization of the yarn. Likewise texturization is increased by using a greater number of grooves per inch. For example, with approximately 150 grooves per inch the permissible depth is of the order of 0.002 inch, whereas with approximately grooves per inch the depth may be increased to approximately 0.004 inch.

In order to enable the shoulder surfaces to absorb a greater part of the pressure asserted and thereby reduce the possibility of damage to the textile material when the resilient roll 3 is pressure-contacted with hard roll 1, the teeth are positioned so that one-third to one-half of h is above the level of shoulders 9 and 11 with the remaining portion of It being below the shoulder level. Such a positioning of the teeth in relation to the unengraved shoulder portions permits the shoulder portions to absorb or dampen out variation in roll pressure which would otherwise be imparted to the textile material and thereby results in a more uniform product which eliminates the side-toside variation in pressure experienced by the prior art.

The improved top roll construction of this invention has greatly lengthened the life of the bottom roll which has been subjected to excessive pressures and as a result thereof did have a tendency to wear away after a relatively short period of time.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. Therefore it is to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described herein.

What is claimed is:

1. In an apparatus for crimping yarn by passing said yarn between two rolls having opposing surfaces provided with alternately depressed and raised areas which engage each other, the first of said rolls having a hard surface in which a pattern of teeth is engraved and the second of said rolls having a surface of resilient material into which a pattern of teeth is formed which meshes with the pattern of teeth of said first roll when the surface of the two rolls are brought into contact with each other under pressure, the improvement comprising providing said first roll with unengraved shoulder portions located on either side of said engraved pattern, the teeth of said engraved pattern extending above the unengraved shoulders a distance equal to at least one-third of the height of said teeth, and providing the portions of said second roll opposite the unengraved shoulders of said first roll with a smooth cylindrical surface of resilient material, during operation both said unengraved shoulders and said engraved patterned area of the first roll pressing against said second roll whereby a more uniform distribution of pressure is achieved between the patterned areas of said first and second rolls.

2. A crimping apparatus according to claim 1 wherein the teeth of said first roll extend above the unengravcd shoulder portions of said roll a distance equal to from about one-third to one-half the height of said teeth.

3. A crimping apparatus according to claim 1 wherein the width of each shoulder portion of said first roll ranges from about 5.3 to 11.7% of the total width of said first roll.

References Cited UNITED STATES PATENTS 10 DORSEY NEWTON,

Dunham et al 19--260 Laros 281.8UX Goodwin et a1. 2872.15X

Atwell 28-72.15 Hollihan et a1 281 .8

Primary Examiner 

